Final Concept
Despite many technical discussions, research and studies, no detailed technical solutions available to the glass walls at the time of dismissal of Utzon in February 1966, but at least the requirements of the architect could be clearly identified in the following way:
All glass walls throughout the Opera House read like one family, with a structural design like.
The structure should be as clean as possible, with minimized if you can not eliminate frame.
The mullions will not be carriers of the shells instead of glass walls will look like hanging from the shells.
The mullions shall, continuous thin fins through the glass walls.
Under the roofs will be the least possible visual obstruction.
Mullion frames are constructed as a number of units of constant section, by marking a way that its position varies continuously across the width of the glass walls.
The question of the uprights of the glass did not exercise as carriers of the shells, but instead the glass walls hang of them was one of the key issues to be resolved in the structure of the facades. A casus of different geometries between the structures and the podium roof, the pillars had to turn outward, in vertical section, thereby achieving a usable flat on the bottom, above that covered by the shells. For the amounts thereof appear to hang was necessary to effectively fix the top and then fall vertically to some extent. This led to a geometry for the two most complex walls, facing the bay in concert halls and theater, the combination of a cylinder and two cones, all with their axes lying in the same vertical line. The top of the glass wall belongs to a cylinder, then it crosses an inclined cone, and it intersects again with a lower cone, continuing in a cut-out as you lower.